Cyrus-imapd memory tuning

[Bron Gondwana]

On Thu, Mar 13, 2014, at 04:18 AM, David R Bosso wrote:
> Just curious about what filesystem (and any special mount options) you're 
> using these days for large cyrus stores.  We've been using ext4 for a while 
> now (we used to use reiser) and have seen performance degradation over 
> time.  I've been wondering if anyone has any positive experience with using 
> recent XFS.

We're using ext4.  We try to recycle filesystems reasonably regularly (add a
new replica, sync everyone up, wipe the old replica), and never let them get
more than about 90% full.

Mount options are:

rw,nosuid,nodev,noexec,noatime,nobarrier,commit=120,data=ordered

(we use devices with battery backed caches, so barrier isn't necessary -
 obviously change that if you're not)

The long commit interval is probably pointless given how liberal Cyrus is
with fsyncs - it's more there to stop temporary files causing IO until they
do get an fsync - in case they are never kept.

Cheers,

Bron.

-- 
  Bron Gondwana
  brong at fastmail.fm